Internal Dynamical Control on Tropical Cyclone Intensity Variability – A Review

The current understanding of internal dynamical processes responsible for tropical cyclone intensity variability is reviewed. These internal dynamic processes are small in horizontal scale and are constrained to characteristics of the vortex itself and less dependent on the environmental and oceanic conditions. Important internal dynamical processes for tropical cyclone evolution are: (i) spiral rainband dynamics, (ii) asymmetric deep convection, (iii) eye/eyewall mixing, and (iv) eyewall replacement cycles. It is shown that while there exists a reasonable understanding of these internal processes in idealized frameworks, there still remains a large gap in our understanding of these processes in the real atmosphere. Additionally, further research is warranted on the interplay of these internal processes with each other as well as their interaction with the environment.